Liver Tumor Ablation

Podcast Transcript

Dale Shepard, MD, PhD: Cancer Advances, a Cleveland Clinic podcast for medical professionals, exploring the latest innovative research and clinical advances in the field of oncology. Thank you for joining us for another episode of Cancer Advances. I'm your host, Dr. Dale Shepard, a medical oncologist here at Cleveland Clinic overseeing our Taussig Phase I and Sarcoma Programs. Today I'm happy to be joined by Dr. Eren Berber, Director of Cleveland Clinic's surgical liver tumor ablation program. He's here today to talk to us about ablation of liver tumors, so welcome Eren.

Eren Berber, MD: Thank you, Dale. Thanks for having me.

Dale Shepard, MD, PhD: Absolutely. So maybe to start, just give an overview of your role here at Cleveland Clinic.

Eren Berber, MD: Sure. I'm a general surgeon and I serve my clinical duties at Department of Endocrinology and Department of General Surgery, where I have a really special interest in neuroendocrine tumors and also specifically on liver cancer.

Dale Shepard, MD, PhD: Excellent. So Eren, I guess I'll let people know that we first worked together back when I was a third year med student and you were a general surgery resident and interestingly, we worked together on cases involving liver ablation, so I held the retractors for many of those.

Eren Berber, MD: Yeah that's right!

Dale Shepard, MD, PhD: Yep. So maybe you can give us a little bit of an idea what, exactly is liver ablation and tell us what that means? What is liver ablation?

Eren Berber, MD: So basically when, where we have a patient who develops a liver cancer, the first option we look for is whether the patient can undergo liver resection where we cut the cancer out. That's the gold standard. However, most patients are not really candidates for this treatment because either they have a little bit extensive disease or they are not really fit for surgery, or maybe the proportion of the liver that you have to remove versus the size of the cancer is proportionately too much. So these patients need some alternative treatment options. So in 2000s, these technologies that use heat to destroy these tumors were introduced. Initially we started with radiofrequency ablation, which is basically like a umbrella shaped needle that you insert into the tumor and when you're under energy, it creates heat and it kills the tumor. The good thing about this, whether you could do it laparoscopically, so instead of making a big cut, you could actually make couple small incisions, each one is less than half an inch or a centimeter, and then you would be able to go find the tumors, burn them, and the patient would be able to go home the next day with recovery within a week.

This was really phenomenal because these patients who had a disease that was not too advanced but they were not really amenable to cutting out, they finally had a treatment option. And the over time the ablation technologies have also evolved from radiofrequency ablation to more powerful technologies such as microwave ablation, and most recently, even more advanced microwave technology that use higher powers to burn these tumors. But the benefit is that obviously you treat these tumors minimally invasively so the patient can go back to their lives or their chemotherapy right away and then you also treat these patients.

Dale Shepard, MD, PhD: So as I understand, we have some pretty innovative technology here at the clinic that we've recently started to use. Can you tell me a little bit about that?

Eren Berber, MD: So if you don't mind, just very briefly, I want to run the history so that we understand why we need this technology. So radiofrequency ablation was introduced in 2000 and it was embraced like a miracle therapy and I think a lot of patients who were not really candidates or had bigger tumors were being reserved. And then we quickly figured out that actually the outcomes of radiofrequency ablation for bigger tumors were not as good. One out of three tumors would recur, meaning that they would come back at the site that you treat and that this was not really favorable.

And then over time microwave technology, which creates it using a different physical property, showed that actually the outcomes for achieving cancer control were much better. Out of 100 tumors that you would burn with radiofrequency ablation, about 30 would recur, meaning come back at the site, whereas with microwave, this was down to about 12%. And then the challenge was that you are not able to treat bigger tumors, you could only treat up to four centimeter tumors, which is roughly an each are half, but now most recently these new technologies that use higher power can burn tumors as big as six, seven centimeters, close to three inches in size, and because you can burn with a higher power, I think that the efficacy and the treatment success is also going to go up as well. So that's where we are with most newer technologies.

Dale Shepard, MD, PhD: So when we think about things like Gamma Knife radiosurgery, some of the advances in treating larger tumors ends up being staged procedures where maybe it will be two sessions in the ablation area. Is this larger tumors with one treatment still?

Eren Berber, MD: Yes. That's the benefit of doing this laparoscopically. Always we have a lot of awesome technologies where the patient doesn't need to have surgery, but the benefit of doing them minimally invasively, laparoscopically, meaning you do surgery but small incisions, that you can burn these tumors, treat these tumors at one session and because you can see what you're doing and you can manipulate the liver around, then you don't have to do it in two sessions. You can do a very aggressive treatments where the tumor can be treated in one session.

Dale Shepard, MD, PhD: Are there particular histologies that this works better?

Eren Berber, MD: A patient with what we call neuroendocrine tumors. They have the best success rate. But historical note that the tumors that were more resistant to burning ablation where the colorectal cancer spreads to the liver, but with the newer technology, especially with this high power microwave technology, we are seeing that actually the success for those tumors have also improved. As I mentioned, the failure rate has gone down from 40% to about 10%, so these new technologies were also able to make this modality an appropriate option for colorectal cancer as well.

Dale Shepard, MD, PhD: So neuroendocrine tumors would be best perhaps the newer technologies, things like colorectal cancer are improving. Are there any tumors that this would be a bad idea?

Eren Berber, MD: The tumor that this is a bad idea actually are the tumors, not by their nature or histology, but their location in the liver. For burning ablation, either you do radio frequency or microwave, the tumors that are close to major bile ducts are not good options because if you burn the bile ducts, you can cause bile duct injuries where the bile duct narrows or the bile spills out and it can cause significant complications. So those are the locations where we will not offer this treatment. Otherwise, any histology, obviously based on oncologic principles, would be a candidate for these options.

Dale Shepard, MD, PhD: We've talked about size of tumors. We talked about histology of tumors. What can you tell me about the number of lesions that could be ablated in any given time?

Eren Berber, MD: So it has to do with how much of the liver surface, the liver volume that the cancers occupy, and then we restrict this to less than 20% of the liver surface or the liver volume, because we burn more liver tissue, then you can cause some liver damage or the patient might experience some symptoms of liver failure after the surgery. But size wise, I would say that, again with the newer technologies obviously, the size is no longer a limitation. It used to be four centimeters. I would say, depending on the circumstance, if you have a tumor up to probably six centimeters without additional disease and it makes sense cancer treatment wise, oncologically, then probably the size limit would be about six centimeters now with these new technologies.

Dale Shepard, MD, PhD: You talked previously about failure rates, and I presume you're talking about local failure rates. What's being done to combine this technology with systemic therapies to more of an adjuvant setting or what's being done to overall treat the patient, minimize risk of new metastasis.

Eren Berber, MD: So obviously, ablation is a complimentary treatment option for these patients, and as you mentioned, especially systemic therapy is a significant part of this multidisciplinary care. So patients with this obviously stage four disease definitely gets systemic therapy, they interrupt, we do the ablation, they go back on the systemic therapy, so they go hand in hand. What we are noticing is actually, when we look at the historical outcomes, especially at the Cleveland Clinic, because of the advances in systemic therapy, overall, the survival outcomes, we talk about the local success rates where you look at, "Okay. I treat the lesion. How often does it come at the site that I treat?" But obviously you want to look at the big picture. "Okay, am I improving the patient's survival or not?" I can tell that for instance, colorectal cancer in 2000, where we had a less powerful technology and then maybe the indications were not so well-defined and we did not have so powerful chemotherapy drugs, for a patient with colorectal cancer, the five-year survival rate was about 18%. But when I look at our results, most recent for instance over the last last 10 years, it's gone up to like 46%, which is close to the outcomes we get when we cut these tumors out. So I think that the advances and the coordination of these treatments with chemotherapy, systemic therapy has really improved overall outcomes for the patients in general.

Dale Shepard, MD, PhD: So oftentimes, you mentioned multidisciplinary care, we have somebody and we've shared patients with a number of different tumors. They may be on a systemic therapy, they develop a liver lesion, you ablate it, would go back on systemic therapy and then maybe they'll get another liver lesion. What kind of time interval do you think is reasonable at this point to think about going back in ablating when we think about patient characteristics? So people might be listening and say, "Well, I have a patient that had an ablation a while back. Can they get another one?" How do you talk to patients about that?

Eren Berber, MD: So obviously, with anybody presenting with any spread to the liver, we want to make sure that we know the biology of the cancer. We want to know how it's going to behave in the long run. So generally, we space these surgical treatments, whether it's resection or ablation, about at least six months apart, because then with six months of monitoring the patient will give you an idea about the natural history and the biology of the disease and you can decide whether the patient would benefit from another surgical procedure.

Dale Shepard, MD, PhD: So far, essentially we've focused on radiofrequency ablation, on microwave. How does this vary from cryoablation? What's the advantage of the types of ablation you do compared to cryoablation?

Eren Berber, MD: Cryoablation actually, it was the first ablation technology introduced end of 1990s and instead of burning the tumors, you were actually freezing the tumors in order to achieve cell death. The issues with the cryoablation were that, first of all, the complication rate was higher. The patient would get very significant complication, including bleeding problems or significant tumor release syndrome, where the patient gets significant inflammatory response after these treatments, and also the outcomes were not as good. The local success rate was way below what we will achieve with radiofrequency ablation or microwave ablation. So therefore cryoablation, despite opening the door for these type of treatments, it has fallen out of favor pretty quickly seeing the advantages of radiofrequency ablation over cryoablation.

Dale Shepard, MD, PhD: What does this look like practically? You mentioned this as being done laparoscopically. Tell us a little bit about what a patient experiences in terms of time that it takes for the procedure, recovery times, things like that as compared to a resection.

Eren Berber, MD: Sure. Basically the patients come to hospital, they have surgery and they receive anesthesia so they don't feel pain, and then they get two small incisions, each one is about an inch in the right upper quadrant of the abdomen. And then the procedure depends on how many lesions we're treating and how much scarring the patient has. If you have a patient who does have a lot of scarring, has a couple of lesions, the procedure will be done within 60 to 90 minutes and we will do a special pain block so their pain is minimal after surgery and they don't have any stitches to remove and they go to recovery. They start on their diet right away and most of the time do not require narcotics and next day they go home.

Whereas, if the patient's undergone open liver resection, the patient then would require a bigger incision that spans along the right top corner of the abdomen and then they would stay about four to six days in the hospital and the procedure will also take longer. Depending on what you're doing, it's going to be anywhere from three to four hours. We are able to do a lot of the resections laparoscopically. Even with that operation, the procedure takes couple of hours and the hospital stay is about two to three days, which is longer compared to an ablation. So if the patient's a candidate for ablation, both the surgical procedure and the recovery would be much simpler than a liver resection.

Dale Shepard, MD, PhD: So you described how we've recently developed some newer technologies, higher power microwave and advances from that, but what are the gaps? What needs to happen for that next step? What are we looking for in terms of improvements from here?

Eren Berber, MD: I think at this point, obviously as you get more options to treat one disease, the question becomes, "Okay, in a given patient, which treatment do we do?" Now we're getting more overlaps. Okay, the ablation technologies are more powerful, the results are better, so the indications are going to overlap with those patients who you would take to surgery and then you would do an all open or laparoscopic liver resection. So which option is better? I think that's the question now, how does this treatment modalities compared with liver resection if the patient's a candidate for both options? I think that's the biggest question now. I know there are some randomized studies that are being done, especially in Europe, looking at patients with, for instance, a small colorectal cancer metastasis and comparing the outcomes of ablation versus resection, cutting them out. I think that's the gap, that we have to figure out which patients are really better for an ablation versus a resection.

I think that the decision for a patient who is not fit to undergo a big liver resection, or those patients have smaller tumors and you would really need to remove half of the liver with a resection, I think the decision is clear, that those patients are better served with an ablation. But what about a patient who has a smaller tumor that's amenable to resection without removal of some or much liver tissue? Shall we do a liver resection or ablation. Currently based on our historical data and training, we are offering resection to those patients, I think which is the right thing to do, but are these new technologies so good that those patients could actually be a candidate for ablation rather than a resection? We don't know the answer yet and I think we need some good data from well done studies to answer this question.

Dale Shepard, MD, PhD: Well, Eren, you've provided some great insight today. Any additional comments?

Eren Berber, MD: I want to emphasize that, again, it's good that we have these new technologies, it's good that we have other treatment options for a patient with liver cancer and I think it's good to kind of be familiar with these technologies and use them complimentary, not really competitive and design a customer treatment tailored on individual patients or each patient might be different. I think it's good to know about these options and use evidence-based data to figure out which option would be best for the patient and one option doesn't really burn bridges and the patient could also be a candidate for the other option on later down the road.

Dale Shepard, MD, PhD: Great. Well, excellent. Well, thank you very much for being with us today.

Eren Berber, MD: Thank you very much, Dale. I appreciate it.

Dale Shepard, MD, PhD: This concludes this episode of Cancer Advances. You will find additional podcast episodes on our website, clevelandclinic.org/canceradvancespodcast. Subscribe to the podcast on iTunes, Google Play, Spotify, SoundCloud or wherever you listen to podcasts. And don't forget, you can access real-time updates from Cleveland Clinic's Cancer Center experts on our ConsultQD website at consultqd.clevelandclinic.org/cancer. Thank you for listening. Please join us again soon.